Self-drilling expansion shell



April 22, 1930. I J. H. PHILLIPS SELF DRILLING EXPANSION SHELL Filed Nov. 24, 1924 Patented Apr. 22, 1930 uNrr JOHN H. PHILLIPS OF CHICAGO, ILLINOIS SELF-DRILLING EXPANSION SHELL Application filed November 24, 1924. 7 Serial No. 751,895..

I My invention belongs to that general class of devices known as expansion shells, and relates more particularly to an expansion shell adapted to be employed in drilling its own hole, into which the shell is permanently expanded and'securedtherein. The invention has among its objects the production of a simple, convenient, inexpensive, durable, efficient, reliable and'satisfactory device of 1c the kind described. More particularly it has as an object the production of a shell which may be satisfactorily used'for drilling purposes, which may be drilled in flush with the outer face ofthe work, which will not distort during the drilling operation, which is substantially self-cleaning, and which may be employed on a percussion or rotary drilling device, or in a percussion device and rocked or rotated during the drilling. It also has particularly as an object an improved construction whereby the expanding unit bolt employed is firmly centered at the outer end of the seated shell. Many other objects and advantages of the construction herein shown and described will be obvious to those skilled in the art from the disclosures herein given. To this end my invention consists in the novel construction, arrangement and combination of parts herein shown'and described, 30 and moreparticularly pointed out in the claim.

In the drawings, wherein like reference characters indicate like or corresponding parts:

Fig. 1 is a sectional view illustrating one form of the device during the drilling operation;

Fig. 2 is a view in elevation of the same expanded; 7 40 Fig. 3 is a sectional view taken substan tially on line 3-3 of Fig. 2; and

Fig. 4 is a sectional view taken substantially on line 4:4 of Fig. 2 the scale being enlarged.

Referring first to Figs. 1, 2, 3 and 4, 1 represents a tubular shell constructed of suitable material and of the desired size and shape. This shell, in the construction shown, is a combined drill and expansion shell; that is to say, it is a shell adapted to be employed in drilling itsown hole, after which the shell is expanded in the hole. The shell lis provided with cutting edges or faces 2 at the operative end, while the opposite end is arranged for seating on or in a suitable chuck. The shell 1, as shown in Figs. 1 and 2, is provided with one or more apertures oropenings 4, which serve to partially weaken the shell so that it may be fractured when expanded, thefweb portion 9, however, pre- 69 venting it from contracting or collapsing, as will be hereinafter described. The openings also permit the escape of material accumulating within the drill'during the drilling operation. The drillcan be drilled in flush without requiring withdrawing the drill to clean or remove the dril'lings, thereby saving time and labor; I

I have shown achuck 5 provided with an extending portion 6 arranged to projectinto the drill. The chuck 5 is carried by any suitable tool, for example, a-percussion hammer which is employed to force the drill into the work 7 which may be concrete, brick or the like." The shell is preferably hardened 5 after it is constructed so that it may have suffioient life to at least drill its own hole.

As most clearly shown in Figs. 2, 3 and 4:, the outer end of the drill maybe formed as indicated at' 3, so that it is not cylindrical but of such shape that it may be preventedwfrom turning in or on the chuck. I have illustrated the same as fiattened'so as to form four sides, and have constructed the chuck part 6 to fit thereinto. Obviously, with this construction the drill may be turned or rocked during the drilling operation, thereby increasing the efiiciency of the drill and speeding up its operation. The flattening at the end of the shell has another advantageof centering the expanding rod thereat, as will be more fully explained hereinafter. The hole in the material is first drilled substantially straight, as shown in Fig. 1, after which an expanderS is inserted in the toothed end of the'drill and the shell then driven into the hole, the expander expanding'the drill end so that the shell is firmly locked in place. It will be noted'by referring to Fig. 2 that when the shell is expanded, the'web 9 is substantially factured, as indicated at 9, adjacent the end of the slot or aperture 4. The material at 9', however, is sufiicient to hold the drill together during the drilling operation and prevent its distortion by compressing or expanding. If the drill was merely slotted with the slots open at the end, there might be a tendency in drilling, and generally would be, for the drill to contract or expand, particularly to contract. By leaving the web at 9, the drill is maintained intact until ready for expansion and then the same is easily fractured by the expander. I have indicated at 10 in Fig. 2 how the hole is belled out at the final drilling operation.

As shown in Figs. 2 and 3, 11 represents a hanger bolt or the equivalent, which ma be provided with a head 12, or a nut, or equivalent fastening device, arranged. to engage with the work to be secured in place, which I have illustrated at 12. By forming the outer end of the drill with the flattened faces at 3 previously described, it will be noted that the same more nearly fits the bolt at the outer end, as indicated at 14 in Fig. 3. Where the wedge or expander 8 also constitutes a nut, as shown in these figures, the bolt necessarily is smaller than the interior diameter of the shell as otherwise the small end of the nut 8 would be too thin at this point. Flattening the end of the shell or otherwise similarly shaping it, therefore, not only provides a nonrotatable engagement with the chuck, but also tends to center the bolt in the shell when the same is of the reduced diameter as shown. In some cases, however, the nut or expander 8 is not threaded, but the hanger otherwise connected with the shell. The chuok 5, re gardless of its construction is made to fit the drill with su'liicient tightness to hold the drill in place, the particular one shown being tapered on the projecting end 6.

It will be noted that the shell is substantially strong and rigid for the drilling purposes without danger of contracting or fracturing, but, when the expander is applied, will be fractured and expanded in the desired point. The same permits the preferred chilling operation, to-wit, the driving in by means of the percussion hammer, and then at the same time rocking or rotating the drill in the hole to. facilitate the drilling operation. 7 Material drilled or broken loose may flow down into the drill, and'during a large portion of the drilling operation may escape Without withdrawing the drill from the hole through the openings in the side walls.

It may be mentioned that it is immaterial as to how the openings are formed in the drills. Ihave accomplished this in various ways, for'instance, by sawing or drilling the holes or apparatus, or by slotting the same from theend and then spot-welding a small hinder or block at the extreme end which forms really a spacer and is the equivalent of the web or spacer portion 9 previously described. Other methods will be obvious to those skilled in the art. With some styles of chucks not shown it may also escape through the chuck or drill holder. The drills are particularly efficient, and may be economically manufactured. Each drill being adapted to drill its own hole and of sutlicient life to so do, the operator is not compelled to re-sharpen his drills repeatedly, nor to work with a dull drill, and in addition, the expense of extra drills is obviated. Also, the operator always has a drill that will drill the proper hole for the particular shell as the shell is its own drill.

.Having thus described my invention, it is obvious that various immaterial modifications maybe made inthe same without departing from the spirit of my invention;

hence I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combination of parts herein shown and described or uses mentioned.

What I claim as new and desire to secure by Letters Patent is:

In a combined drill and expansible shell, a tubular body provided with cutting teeth at one end and weakened from a point spaced from but adjacentthereto to a point intermediate the ends, the opposite end being reg ularly formed on its exterior and of a reduced internal circumference and constructed to operatively non-rotatably engage asuitable chuck during the drilling operation and closely fit a hanger bolt thereafter projected "5 into the shell.

In testimony whereof, I have hereunto signed my name.

JOHN H. PHILLIPS. 

